中空ねじり試験機を用いた豊浦砂の変形特性に関する研究

抄録

A series of stress probe tests on Toyoura Sand is fully described in this paper after introducing preliminary works related to (i) the measuring system of the volume change of the specimens, (ii) creep behaviour of sandy specimens and (iii) effect of the slight scattering of initial void ratio of the specimens on the test results obtained from a hollow cylinder apparatus designed for testing sand. The tests results are interpreted based on the concept proposed by Jardine (1985&1992) who introduced three yield surfaces representing the boundary of linearlyelastic behaviour, nonlinear elastic range and elasto-plastic range. Ten series of stress probe tests in ten different range of stress area in the stress space gives a clear evidence of the isotropic hardening (proportional expansion ofyield surfaces) induced by anisotropic repeated loadings.